A mine drainage system is an important part of mine safety production. A centrifugal water pump is usually used in the drainage system. A gate valve is an essential element in this system. A traditional electro-hydraulic gate valve actuating device is mainly composed of a motor, a hydraulic cylinder, a hydraulic pump and a hydraulic valve. The electro-hydraulic gate valve actuating device with this structure may generate the following problems during application: (1) emergency opening/closing functions are poor; for example, the electro-hydraulic gate valve actuating device cannot be operated normally in case of repair or sudden power failure; and (2) opening and closing speeds of the gate valve are inconvenient in automatic regulation, and a water hammer phenomenon is easily generated.
In a hydraulic controllable gate valve disclosed with publication number of CN200510048257, the gate valve is opened and closed by means of rotary motion of a lead screw driven by a hydraulic motor, but this rotary motion is still traditional output rotary motion, not direct-push output. An emergency function is not set, and bidirectional speed regulation of opening and closing cannot be realized.
In a gate valve electro-hydraulic drive system with the function of emergency valve closing and a gate valve disclosed with publication number of CN204828870U, the gate valve electro-hydraulic drive system includes a motor, a hydraulic pump, an integrated control valve, an accumulator actuating oil cylinder and a hydraulic oil tank. A manual pump is adopted for manual control. Although this system has the function of emergency valve closing, this system cannot achieve bidirectional speed regulation of opening and closing of the gate valve.
Therefore, it is very important to design a gate valve actuator having compact structure and capable of being used in emergency sudden situations and eliminating a water hammer by means of bidirectional speed regulation of opening and closing.